The present invention generally relates to liners for cargo containers, and to a method of installing a liner inside a cargo container.
Standardized containers or boxes have come into very extensive use for the shipment of freight by land and sea, and the many advantages of such containers have made it extremely desirable to adapt them for use with as many types of cargo as possible. Accordingly, there have been attempts, with varying degrees of success, to use conventional containers to carry bulk cargo such as dry bulk chemicals, powdered and pelletized resins, flour, coffee and grains.
When cargo containers are used to carry such bulk cargo, it is important that the container itself either be kept clean or be cleaned after each load of cargo is emptied from the container, so that the container can be subsequently used with another load of cargo. Moreover, it is important to protect the bulk cargo from contamination and from undesirable exposure to the natural elements.
For these reasons, large plastic removable liners are often used to line the interior walls or surfaces of the cargo containers that are used to carry bulk cargo. The liner protects the cargo during shipment, for example, from rain and debris; and after the cargo is delivered, the liner can be removed so that the container is again usable, without significant cleaning, to carry other cargo.
Various difficulties have been encountered, however, in using plastic liners in the above-described manner; and in particular, it has been found that the liners often tear or rupture under certain conditions. For example, a cargo container carrying bulk cargo is often emptied by opening the rear doors of the container, and raising the front end of the container to tilt the container so that the cargo slides out the back of the container. Prior art container liners often tear or rupture as the cargo slides rearward through the container and over the liner. Numerous attempts have been made to solve this problem by using braced cardboard or wood bulkheads to help support the liner inside the container, or by hanging the liner from the container roof or walls by means of a multitude of hooks connected to the top perimeter of the liner. These prior art attempts have not been completely successful; and it is believed that this is due, at least in part, to the fact that the exact specific factors causing liners to rip or tear have not been completely understood.